Compact High Gain Resonant Cavity Antenna With via Hole Feed Patch and Hybrid Parasitic Ring Superstrate

A compact and high gain resonant cavity antenna (RCA) is investigated in this work. At first, a ray-tracing model and the full-wave analysis are presented to clarify the characteristics of RCA in cases of finite lateral size and inhomogeneous superstrate. In consequence, a novel compact, high gain, and wideband RCA is proposed. The RCA consists of a via hole feed patch and an array of hybrid parasitic rings fabricated on a superstrate. The via holes feed patch with a high radiation directivity significantly enhances the RCAs gain. On another hand, the dimension and bandwidth of the RCA are improved by the hybrid parasitic ring superstrate which is constituted by non-periodic parasitic patch and rings. Finally, a prototype of the RCA is fabricated and measured. With only the dimension of $1.35\lambda _{0}\times 1.35\lambda _{0}\times 0.63\lambda _{0}$ , the peak gain of 15.8 dBi and 3 dB gain bandwidth of 10.7 are obtained.